A liquid crystal display panel including a first substrate, a second substrate, and a liquid crystal layer interposed between these substrates is known. Ions resulting from impurities or ions eluted from a sealing member which sticks the first substrate and the second substrate to each other often enter the liquid crystal layer. If the ion density becomes locally high in the liquid crystal layer, the effective voltage applied to the liquid crystal layer at this part may be lowered. In accordance with this, the luminance at the part may be lowered and a display image may be affected by black non-uniformity in display or the like.
A technology of disposing an electrode in a peripheral area outside the display area and trapping ions by the electrode to prevent the degradation in display quality in a display area has been proposed. Further improvement in the display quality and reliability has been required for such a liquid crystal display device comprising the electrode for trapping the ions.